RNA viruses, and more specifically their nucleic acids, are one of the most difficult biomolecules to stabilize because of both chemical self-hydrolysis and enzyme-mediated degradation. The temperature of sample storage is often a key determinant for the quality of the RNA virus sample and, therefore, samples containing RNA viruses are typically maintained and shipped in refrigerated states (i.e., 4° C. or less). Further, handling of virus containing samples is precarious due to risk of viral infections, if the sample cannot be rendered inactive.
Accordingly, current methodologies for preserving nucleic acids, such as RNA, under ambient conditions in a liquid state have focused on deactivation of RNases through the use of, for example, detergents, chaotropic compounds, reducing agents, transitional metals, organic solvents, chelating agents, proteases, RNase peptide inhibitors, and anti-RNase antibodies. Additional efforts have focused on modifying RNA chemically in order to prevent trans-esterification and self-hydrolysis.
Most commercially available RNA preservation products can only preserve RNA in a liquid state for days or weeks at room temperature. Technologies that claim successful collection and preservation of RNA in a dry format typically require that the RNA is first “pre-purified” and concentrated from the biological material (e.g., biological samples such as blood, serum, tissue, saliva, etc.) prior to storage of the RNA.
Accordingly, methods and devices that integrate nucleic acid extraction, stabilization, and storage/preservation from a biological sample within a single process are desirable and needed. Further, for safe handling, biological inactivation of the virus is also desirable. Such method and devices would permit long-term storage of nucleic acid under ambient conditions and allow the intact nucleic acid to be rapidly tested or recovered for further analysis without the burdensome handling requirements associated with an infectious substance.